Geosoft - Exploring With Data

Drag and drop shortcuts in Oasis montaj - time savers and hidden gems

A question came through our twitter feed asking what is the best way to import many XYZ files into Oasis montaj.  The answer:  Select all the XYZ files in Windows Explorer, drag them and drop them into a new, empty Geosoft database.  

There are several useful drag-and-drop shortcuts in Oasis montaj and Target, but because of their nature (they are drag-and-drop methods after all!), they can often be overlooked when they are most helpful. 

Drag-and-drop can be used to:

Simplify multi-file operations:

• Drag-and-drop a Geosoft map, grid, or database from Windows Explorer into Oasis montaj.  This is a quick way to add files to a new Project.
• Drag-and-drop a map, grid, or database from the Project Explorer to the Oasis montaj desktop. This is a quick way to open these file types.
• Drag-and-drop XYZ files to a new database.

Move map groups from one map to another:

• Drag-and-drop a grid from the Project Explorer to an open map.  (This is the same as Display Single grid, and if the auto-shading option is on, the dropped grid will be shaded.)
• Drag-and-drop a single map group from one map to another map. (This is the same as right-click option to Copy and Paste Georeferenced.)

Transfer map layers from 2D maps to 3D views:

• In Oasis montaj 7.5 you can drag and drop map layers from Target section maps to the 3D Viewer and the layers will appear georeferenced in 3D space. 

You can see some of these drag-and-drop methods in action in this video.

3D Earth Modelling in the Cloud: The Geosoft VOXI development story

Released in April, 2012, Geosoft’s VOXI Earth Modelling service gives exploration geophysicists the ability to convert magnetic and gravity data directly into useful 3D Earth models that can be integrated with other 3D exploration data.

Creating the cloud-based VOXI inversion service took us over three years, and required the work of 29 people on a number of development teams. This is the story of how we did it.

3D Earth Modelling and Exploration

Three-dimensional Earth modelling of geophysical data has been an important part of exploration geophysics for over a decade, allowing explorers to transform 2D data into detailed, subsurface 3D models useful for defining exploration targets in areas of complex geology.

The science behind 3D inversions has been in development within academic environments even longer. The University of British Columbia Geophysical Inversion Facility (UBC-GIF), a leader in this area of research, was founded in 1989. The UBC-GIF consortium for Joint and Cooperative Inversion of Geophysical and Geological Data (JACI) pioneered the developed practical inversion algorithms that have been used in real exploration since the 1990s.

It’s our view, however, that the full potential for 3D inversion in exploration has continued to be limited both by the complexity of the tools and the need for powerful computers. With VOXI, our goal was to address both of these challenges and make 3D Earth Modelling accessible to more explorers and be more impactful to exploration success.

Behind VOXI’s development

VOXI development began in 2009, the year Dr. Robert G. Ellis joined Geosoft as a Senior Scientist for Earth Modelling. As a co-founder of the UBC-GIF, and a collaborator with UBC and other modelling groups over 20 years, Rob is a renowned expert in 3D geophysical inversion. Rob and Geosoft embarked on a shared mission: to build the next generation 3D earth modelling system that would combine Rob’s accumulated knowledge with the latest available algorithms and commercial development techniques in use at Geosoft.

We also saw the opportunity to harness cloud computing to provide super-computing power to everyone. The cloud presented us with both challenge and opportunity. Using cloud computing meant interpreters would not be limited by the processing power of their computers, which is a huge benefit for process-intensive applications like 3D inversion. Our challenge was to scale VOXI so that hundreds of geophysicists could run large inversions at the same time, and from anywhere in the world.

Scaling for cluster computing

With Rob's knowledge of the science of 3D inversion, in less than 6 months we were able to build the latest generation of inversion from both open-source libraries and our own original development. Then came what turned out to be the really hard work – making the system work on multiple-cores in a cloud environment, and making it easy to use.

Our first scaling work was done on a conventional 96-core computing platform hosted in the “cloud” by Rackspace in the USA. All our multi-threading and cluster-computing development was proven here, and we were able to achieve some impressive performance numbers with Ivanhoe Mines as a key early collaborator accessing the service from Australia.  But we still faced the challenge of how to make VOXI scale so that many geophysicists could run large inversions at the same time, and from anywhere in the world. For that we turned to the Microsoft Azure platform.

True Cloud computing

Azure was important to us in a number of ways. First and foremost was the level of commitment that Microsoft has made to Azure, which has the ability to support our exploration customers anywhere on earth with 6 international data centers, each with up to 3 million processing cores. Microsoft also had both the business models and the tools we needed to be able to scale as demand required.

But developing for a true cloud platform is not straight-forward, as we would find out.  Building a multi-core cloud-based algorithm is very different from building a program that runs on a workstation or local cluster. The effort to re-engineer VOXI for Azure took us most of a year to get right.

Making VOXI usable

And as any commercial software company knows, building software to be usable is a challenge in its own right. We worked very hard with our collaborators over two years to design and improve the interface so that everything would work as smoothly as possible and fit within an explorer's natural workflow. The user-interface development work required yet another full-time development team.

Summary of the benefits

We feel the outcome has been well-worth the journey, and we are excited about the benefits we see for exploration:

• All explorers have super-computer access to build large models in minutes.
  One early VOXI customer compared the VOXI service performance to his current desktop modelling program. Given exactly the same model, what took four hours with his current software was completed by VOXI in under 2 minutes - more than 100 times faster.
   
• 3D Earth modelling is now practical and user-friendly for all geophysicists.
  VOXI runs with a minimum of user effort directly from Geosoft Oasis montaj, an industry-standard platform for working with geophysical data.  It just works, naturally, and seamlessly.

What’s Next?

VOXI has been our largest and most comprehensive development to date. The work we have done with VOXI lays the foundation we need to build more useful cloud capabilities for explorers in the years to come, including more 3D modelling methods, support for larger models and new ways to harness cloud computing to benefit exploration.

Free Sources of Geoscience Data

Occasionally I am asked about my favourite (and most useful) sources of publicly available online data. Here are some of the ones I’ve used and can recommend:

• If you are working in Canada, the Geological Survey of Canada’s Geoscience Data Repository is a great source for regional and survey scale datasets.  It includes extensive Aeromagnetic and Electromagnetic data with simple instructions for viewing and downloading the data using a mapping application that is based on Geosoft DAP technology.


• Many global scientific and government organization host data online, or you can order it (sometimes for a small processing fee). A few that I have used include: Geoscience Australia - this site has many geophysical and geological datasets; USGS EROS Center - links to several data discovery tools; NOAA National Geophysical Data Center - Data by Discipline links to some great resources; and USGS LP DAAC - links to resources for ASTER data.


• Provincial and state geoscience surveys are also a great source of geoscientific data.  I recently attained a copy of New South Wales’ Explorers Directory 2012 with GIS data in Esri and MapInfo formats and a great selection of imagery.  For cultural and geographic data, the datasets provided with Esri and MapInfo applications are a good start. In the US, data.gov has a growing collection of spatial data in many formats.


• Compilations are often sponsored by a group of government and educational groups to make data publicly available and easily accessible, including numerous programs like Geomagnetism, a NOAA/CIRES project;  OneGeology, an international effort to collect geological data at 1:1 million scale; and ASTER GDEM, a joint NASA JPL program to collect high resolution ASTER data for the world.

I’ve posted on the Geosoft DAP Server before.  The SRTM data on the Geosoft DAP Server is very handy, and there are some other large, low-res datasets available here as well. Datasets can be windowed and reprojected and reformatted as needed with very little effort. 

I hope you find this list helpful. I’d be interested in hearing about some of your favourites!

Target for ArcGIS Sneak Peek

The Geosoft 2012 release will be available soon. One of the improvements that I am most excited about are three interconnected features in Target for ArcGIS that connect Sections to 3D.

Display: You can send map layer(s) from a Target for ArcGIS data frame to the Geosoft 3D Viewer. Layers from Sections or Plans will appear in their correct geospatial orientation in the 3D view.

Export: You can export 2D interpretations from Section or Plan to 3D Shapefiles or 3D DXF files. These new 3D files can be opened in the Geosoft 3D Viewer, Esri ArcScene, and other 3D applications.

Import:  You can include 3D Shapefiles and 3D DXF files when generating a Target for ArcGIS Section. These 3D files will appear correctly located on the Section.  3D DXF files are sliced to display the intersection with the Section; the entire 3D Shapefile is projected on to the centre slice of the Section.

These new capabilities improve the connection between 2D and 3D in Target for ArcGIS.

Gridding algorithms - which one do I choose?

A customer commented recently that the kriging algorithm was taking a lot of time to complete for a large dataset.  Kriging is computationally expensive and because his dataset had several million points, we suggested he try IDW, direct gridding or minimum curvature instead.

Here is a list of the gridding algorithms available and a brief description of why they might be chosen:

Minimum Curvature can be used when data is sparsely sampled and the surface is expected to be relatively smooth or continuous between data points.

Kriging is a geostatistical method that determines the most probable value at each grid node based on a statistical analysis of the entire data set.  Because of this, it is computationally expensive. Kriging can be used if the data is variable between sample locations, known to be statistical in nature, or for poorly sampled/clustered data. This algorithm is available for 2D and 3D gridding.

Bi-directional line gridding is designed to rapidly interpolate roughly parallel line-based data, especially if there is a high sample density down the lines relative to the line separation. The interpolation uses linear, minimum curvature or Akima splines. It is only available in Oasis montaj and cannot be used to interpolate randomly distributed XYZ data.

Tin gridding results in output grid cell values that closely match the magnitude of the original data at known XY positions.  The interpolation is entirely local and every point will be influenced either by its nearest or natural neighbours depending on the parameter chosen.  Tin gridding can be used for irregularly sampled data. This algorithm is available in Oasis montaj and Target.  In Target for ArcGIS, this algorithm is only available when gridding drillhole data for a plan maps, section maps or plan grids in 3D maps.

Inverse distance weighted gridding (IDW) can be used when data is sparsely sampled and the surface is not expected to be smooth or continuous between data points. The data points are weighted so that the influence of one point relative to another declines with distance.  Three key parameters that can be set that will influence the interpolation are search radius, weighting power and weighting slope. IDW can be used to create 2D grids and in the April 2012 release, IDW will also be an option for 3D gridding.

Direct gridding is designed for highly sampled or oversampled data such as LiDAR.  The output value will be determined based on the minimum, maximum or the mean of the data points that fall within the grid cell. This algorithm is available in Oasis montaj and Target for 2D gridding.  In the April 2012 release, direct gridding will also be an option for 3D gridding in Oasis montaj.

Getting the most from the Support Knowledge Base

A searchable support Knowledge Base is available on geosoft.com. There are 4 article types, each corresponding to a tab in the Knowledge Base.

How To articles outline the use of a tool, or a series of tools to achieve a specific task.

Troubleshooting articles describe a specific problem that is encountered due to a misuse of a tool or they describe a problem with the tool itself. Resolution steps describe proper use of the tool or a work around if there is a known issue with a function.

Error Messages articles will state the exact error message that is encountered and the possible steps to resolve the problem. The cause of the error message will also be listed if it is known.

General Information articles contain information not directly related to completing a task. They may include material on theory, policy, compatibility, etc.

After you type in your keywords and click Search, the Article Type tabs will show how many articles have your keywords in them. For example, if you type in a few keywords from an error message that was displayed when attempting to run a function, you need to click the Error Messages tab to see the relevant articles. You can further narrow down the search results by selecting the Geosoft application you use from "Filter by product".


There is a Submit Feedback button at the bottom of each article. Send us your comments or suggested improvements for the article(s) you found.

Coordinate Systems: Set it and forget it

Someone asked me at Roundup about a grid that was not displaying in their map as they expected. It turned out that the map's data view did not have a coordinate system and the grid was referenced in a different coordinate system, so it didn't reproject on-the-fly.  This could happen to anyone!  Here's a bit of advice to keep it from happening to you:

Import, Set, Save.

When you import a new dataset, often to a Geosoft Database (*.GDB), be sure to set the coordinate system right away using the Coordinates menu Coordinate System... option.  This will ensure that all grids, maps, and other datasets that you create from this database will also have a coordinate system. 

Then save your work. I like to use the Save Project toolbar button.

Preparing for PDAC 2012

Geosoft is at the ASEG in Queensland, Australia this week, and we’re preparing for PDAC 2012, which starts Sunday. If you’re planning to attend PDAC, take a look at our events page for a list of Geosoft presentations during the show, and training sessions after PDAC. You’ll also find a short list of what’s new and interesting at PDAC 2012 on Earth Explorer.

Some Geosoft highlights:

• Saturday’s KEGS Symposium: At 9:40am, Robert Ellis, Geosoft is presenting on the Inversion of Magnetic Data from Remanent and Induced Sources.

• Tuesday’s PDAC Geophysics Session: At 4:05 pm, Ian MacLeod, Geosoft is presenting on the VOXI Cloud Approach to Earth Modelling for Exploration.

• Monday and Tuesday: From 11:30-4pm daily, presentations on using Geosoft software and technology for exploring in ArcGIS; managing your mapping projects and exploration data; and visualizing your geology drillhole and borehole data at the Geosoft Booth #931.

• Sunday to Tuesday: At 4PM, introduction of VOXI Earth Modelling at the Geosoft Booth #931.

• Training after PDAC: Software training courses are available March 8-9, following PDAC, for Target for ArcGIS, Target and Oasis montaj. View the schedule.

The Geosoft team is looking forward to showing you what’s new, and what’s coming in this year’s software release, which is scheduled for April. We’ll be posting more on the topic of the 2012 software release next month. 

Updating Target Plan and Section Maps

Updating section maps is a common task for Target users.  This topic came up more than once at the Roundup and I have written about it before.  There are three main ways that you can update your Target maps. The first two have been outlined in earlier posts.

1. Recreate Target Section or Plan Map - This option is available by right clicking on the Target map and will open the plotting tool with all the parameters from the current map.  If you don't change anything, then your map will be overwritten with updated data from the drillhole project.  This was described in Recreating plots and replotting holes in Target

2. Replot Holes on Target Section or Plan Map - This is useful when you have a map with annotations or interpretations but need to update the map with new holes or new downhole data.  The map is not overwritten, so any custom layers you have added are maintained but the hole traces and downhole data groups are updated with the most recent data.  This was also described in an earlier post: Replot Holes on Existing Plan or Section.

3. Map Tag Names or Save Map As - The third option allows for a little more freedom, especially when you have additional groups such as images, interpretations, or other imported data in your plan or section map.  The first step is to use different names for the original and updated maps. One way to do this is to change the "Tag Name" when recreating the section or plan (as described in #1).  I often forget to change the tag name when recreating the section or plan so I like to use Map > Save Map As to save the original map with another name.  Appending the date at the end of the file name works well.  Then the additional groups in the original map can be added to the updated plan or section by selecting them (use Ctrl to select multiple groups) in the Map View/Group Manager and dragging and dropping them into the section view.

Displaying Drill Hole Data More Effectively in 3D

For my first Roundup-inspired post, I picked a topic that every explorer I meet is interested in – working more effectively in 3D.

Displaying drill holes in 3D using DH-Plot > 3D Map is a convenient way to create a 3D map, complete with a legend, showing selected holes, topography, and two types of data.  Here, as may often be done in a 2D section, lithology has been plotted as a Rock pattern and gold assays are displayed as a Bar plot.  It is easy for this to become cluttered, making it hard to see significant characteristics in your data.

 
In order to start from a cleaner, less cluttered view of your data, try this instead:

1. Use DH-Plot > 3D Map to create the 3D map of the selected holes in the drillhole project, but leave the Data tab blank. For an even cleaner starting point, try turning off the "Depth Ticks".

2. In the 3D Viewer, select the Add to 3D > Drillholes menu option.  Instead of plotting the geology as a Rock pattern, display only important geological intervals using discrete values in a Text band.

 
Discrete intervals in the Number bands option is also a good way to display significant ranges from assay results.

3. In order to display other types of data using the Add to 3D > Drillholes menu option, first rename the existing group.  Then you can toggle this layer on and off as you build your 3D data groups.

 
Now use the Add to 3D > Drillholes menu option to add more geology intervals or other downhole data.

4. Finally, add the Topography grid to help orient your 3D view relative to the surface.